1. Field of the Invention
The invention disclosed and claimed herein generally relates to detent apparatus for a positioning mechanism or actuator assembly for a tape transducer. More particularly, the invention pertains to detent apparatus of the above type wherein a magnetic force is used to firmly retain a tape transducer in one or more selected positions. Even more particularly, the invention pertains to detent apparatus of the above type wherein the tape transducer comprises a read/write head for a data storage arrangement using magnetic tape.
2. Background of the Invention
In a common data storage arrangement using magnetic tape, it is necessary to move the read/write head to different positions with respect to the tape. More particularly, the tape head, which is provided to selectively read data from and write data onto the tape, may need to be moved laterally across the width of the data storage tape. This may be necessary to place the head in operative relationship with any of two or more data bands or tracks positioned along the tape length.
In view of the above requirements, tape head actuators have been developed, to move the tape head from one band to the other. Some of these actuators have two modes of operation, a first mode for moving the tape head between bands, and a second mode for maintaining alignment between the head and a particular data band. Prior art devices of this type are disclosed, for example, in U.S. Pat. No. 6,437,946, issued Aug. 20, 2002.
In prior art tape head actuators as described above, a latching or holding mechanism of some type is generally provided to retain the tape head in place, after the head has been moved into position with respect to one or another of the bands. The retaining mechanisms currently available tend to use spring retainers or detents, and have mechanical components in contact with one another. Vibration or relative motion generally occurs in a tape actuator during tape movement. As a result, reliability and performance problems have been encountered, resulting from such things as component fatigue, component wear and unpredictable frictional forces at detent component interfaces. More particularly, the vibratory movements cause retainer components to rub together, generating friction. Moreover, the rubbing action can cause undesirable debris to be generated and to fall into the actuator or onto the tape or tape head. Also, use of a spring in a head actuator retainer or detent can allow vibrating motion that is of an unpredictable nature.